Variable length envelope

ABSTRACT

This invention is an envelope that can be laterally extended to accommodate articles of varying length. The envelope is formed from a single blank in one pass in a continuous manufacturing operation.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

[0001] This invention is an envelope that can be used by a first user in a compact length configuration, and extended for use by a second user in an alternate length configuration, keeping the envelope contents flat. The extendable feature of the invention provides practical utility where the dimensions of the envelope's contents may vary, or where multiple uses of the envelope are desired.

BACKGROUND OF THE INVENTION

[0002] Mass mailing operations such as bulk mail advertising and delivery of account notices are used by innumerable merchants and financial institutions to communicate with existing and prospective customers. Each piece of such mail typically must be inexpensive enough to compensate for a low rate of return, but must also function as a return envelope of a specific size, for example to hold checks of fixed size. In addition, there is an increasing awareness that minimizing the number of steps that the recipient must follow to respond to a billing statement increases the likelihood of a prompt return. A desirable mailer would therefore be one that combines the features of variable capacity, for example to accommodate response forms or checks of varying length, and ease of use as well as printability. Low manufacturing cost is also of importance.

[0003] Several envelopes have been developed that address the issue of providing flexible capacity. U.S. Pat. No. 1,010,282 discloses an envelope that can be adjusted to different sizes to accommodate multiple documents. The envelope body has auxiliary inner and outer closing flaps secured by glue or other means at its ends, these flaps folding inwardly to be superposed over the envelope body. The outer closing flaps have cutaway portions at which are arranged tongues extending in the direction of the flap, and which are inserted into openings along the length of the flap to keep the envelope closed. U.S. Pat. No. 3,552,640 (Young) relates to an envelope with pleated side flaps forming folded gussets that unfold to expand the envelope into a box-like configuration. U.S. Pat. No. 3,817,445 (Greason) discloses a mailing envelope that has two panels joined by an adhesive to form an expandable pocket. The expandable feature is provided by an accordion fold between the longitudinal edges of its two panels. U.S. Pat. No. 5,398,866 (Bluemle) describes an envelope with pleated side flaps that form a box-like gusset for depth-wise expansion. The side flaps are constructed as side portions of one panel that are foldable longitudinally, with side tongues at their bottom ends. The bottom side tongues serve for closing and adhesively bonding the side flaps to the envelope bottom. The pleated or folded expansion means described in these patents have however been found to be bulky, thus creating difficulties in stacking and bulk packaging of the envelopes. The closure means using tongues are also fully complex, expensive to manufacture, and less amenable to automated processing.

[0004] Despite the advances represented by the foregoing patents, there has not yet been developed an envelope that provides a cheaply manufactured, variable length envelope made from a single high-speed manufactured blank that remains almost completely flat in fold expanded form, and which provides a secure closure whether it is compactly folded or extended to its maximum length. There is also a need for an envelope that is highly machine-compatible in that it can put through an automated device to open and remove its contents.

SUMMARY OF THE INVENTION

[0005] The invention comprises an envelope that may be adjusted by operation of a foldable flap to provide varying lengths for accommodating inserts of different sizes.

[0006] In one aspect, the invention is a variable length mailer comprising:

[0007] a) a front panel having a first fold line and a second fold line in parallel relation one to the other; said front panel having an extension at one end thereof, this extension being alternately foldable in a vertical plane in relation to the first or second fold line;

[0008] b) a rear panel approximately equivalent in length to the length of the front panel and of lesser height than said front panel, said first and second fold lines of the front panel extending along the rear panel;

[0009] c) a top flap approximately equivalent in length to the front panel, said first and second fold lines of the front panel extending along the top flap; and

[0010] d) at least one extendable side flap foldable along either the first or second fold line of the front panel to provide a mailer adjusted to varying lengths.

[0011] In another aspect, the invention comprises a blank for forming a variable length mailer comprising:

[0012] a) a front panel having a first fold line and a second fold line in parallel alignment to each other, and further having an extension at one end thereof that is of approximately the same height as said front panel;

[0013] b) a rear panel approximately equivalent in length to the front panel;

[0014] c) a seal flap approximately equivalent in length to the front panel, said first and second fold lines extending along the top flap;

[0015] d) a first side flap of fixed length and height, the length thereof being less than the length of said front panel and the height thereof being approximately equivalent to the height of said front panel; and

[0016] e) a second side flap cooperatively attached to said extension of the front panel.

[0017] Advantageously, the blank is folded and permanently sealed at one end, preferably on the leading or stamp-edge side of the envelope to provide easy machine feeding. Adhesive means used at this end may be of a conventional variety, such as a construction gum or glue. Typically, the blank includes fold lines forming the side, top and bottom edges of the envelope when folded. In addition, the blank of the invention includes a pair of parallel positioned fold lines, a first fold line for folding the adjustable flap and the extension of the front panel in toward the envelope interior to provide a more compact folded envelope, and a second fold line spaced apart from the first fold line in a parallel relationship such that when the adjustable flap is folded along this line, the length of each of the front and rear panels is correspondingly increased and, as a result, the envelope is extended lengthwise. Scoring or folding along these and the other fold lines forming the envelope edges is provided by conventional means, and is particularly desirable along said first and second fold lines to ensure consistent and precise refolding. In this manner, even overlaps are formed that provide an even thickness, which is of benefit when the envelopes are packaged or stacked.

[0018] The adjustable flap is unattached by adhesive to the rear panel. Accordingly, when the envelope is folded, stuffed and closed in either the compact or the extended position, the adjustable flap is held in place beneath the free edges of the rear panel and is thus prevented from being disengaged. The contents of the folded envelope are further protected by corner overlaps that fold inward toward the corners of the envelop when the adjustable flap is engaged. The folded corner overlaps prevent access to the envelope contents without breaking the seal, and also provide reinforcement of the envelope corners. Preferably, the seal flap seals across all panels and exposed edges of the envelope body to provide an additional measure of security.

[0019] The blank may suitably be cut from paper of suitable grade for envelope construction. The paper may be printed with graphics or suitable instructions prior to cutting, or alternately, any desired printing may be performed after individual blanks are cut. The blank may be delivered folded, flat and per ordered size and ready for automated processing.

[0020] In a preferred embodiment, the envelope of the invention is formed to adjust between two pre-determined lengths, one of more compact length used by a first user for example, for mailing a payment envelope to a second user. This second user then has the option of using the envelope in extended form for holding a longer insert such as a commercial sized check.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is an isometric view of a partially folded envelope according to the invention showing a variable length flap at one end.

[0022]FIG. 2 is a two-dimensional view of a blank according to the invention.

[0023]FIG. 3 is a planar view of a closed envelope having an inwardly folded variable flap according to the invention.

[0024]FIG. 4 is a planar view of a closed envelope with a variable flap in fully extended position according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0025] The various embodiments of the invention may be further described in relation to the accompanying figures. As shown in FIGS. 1 and 2, one of the many embodiments of the invention entails an envelope 1 comprised of a side flap 2 of fixed length in relation to the envelope body, and a variable length side flap 4 formed in part by an extension 3 of panel 14. Panel 3 is disposed in internal relation to the outer edge of flap 4. Flaps 2 and 4 are foldably connected via fold lines 10, 11 and 13 to a front panel 14. Fold lines 10, 11, 13 are preferably pre-scored so that re-folding of the envelope 1 is consistent. Front panel 14 is connected via fold line 9 to a seal flap 6 having an adhesive region 7. Adhesive region 7 may be composed of a suitable adhesive material such as a self-moistening or water-reactive gum, polymer or other glue substance. Front panel 14 is also foldably connected via fold line 12 to a rear panel 5. Rear panel 5 is of approximately equivalent length to the panel 14 and extensions 2 and 3. Extension 3, which, when fully extended, forms part of adjustable flap 4, is supported at the top and bottom ends thereof by corner overlaps 8 which assist in retaining the envelope contents and providing added security to the envelope's corners when it is folded.

[0026] In the embodiment of the invention represented in FIGS. 3 and 4, it should be noted that the rear panel 5 is permanently affixed by glue or other suitable adhesive means along an adhesive region 16 to the exterior of side flap 2 to provide one closed end. There is no adhesion, however, between rear panel 5 and the outer surface or edges of adjustable flap 4 and extension 3. By this means, the extension 3 can be unfolded and the flap 4 withdrawn from the interior of envelope 1 to lengthen the envelope as desired.

[0027] As further shown in FIG. 3, the envelope 1 may be used in a compact, folded position in which the side flap 4 and extension 3 are folded along fold line 10 toward the center of panel 14, while side flap 2 is also folded in inward relation to panel 14, and edge 15 of rear panel 5 is folded upward and over the edges of panels 2 and 4 and extension 3. By this means the envelope 1 is closed and may be secured after it is filled with the desired contents, by moistening or otherwise activating the sealing function of the adhesive region 7 of seal flap 6. When the seal flap 6 is closed, it is adhered over the exposed edge 15 of the rear panel 5, the side flap 2, side flap 4 and extension 3. Alternatively, as shown in FIG. 4, the length of the envelope may be adjusted by unfolding extension 3 before inserting the contents and sealing. When the seal flap 6 is closed, it is adhered over the exposed edges of the rear panel 5 and side flap 2 as well as side flap 4. Because in either of the selected length positions the seal flap is affixed to all the exposed edges, a more secure envelope is obtained.

[0028] The security of envelope 1 is enhanced by the presence of folded overlaps 8, which prevent the formation of gaps when envelope 1 is in fully extended form. The foldover action of the overlaps 8 also provides added security to the corners of the envelope 1, making it less susceptible to tearing, which is a frequent problem associated with the use of automated mail opening machinery.

[0029] The blanks and envelopes of the invention provide a cost-effective means of providing envelopes that can be used for multiple mailing applications, for example to accommodate checks of varying lengths. Use of the envelope in the compact length allows it to be inserted inside another mailer and also saves on postage paid by the end user. The envelopes may be folded with even overlaps to provide a relatively even thickness across all panels for packing and stacking in automation. Thus, the problem of uneven and bulky stacking found with gusset envelopes having, for example, pleated or box folds is eliminated.

[0030] The expanding design of the envelopes also allows automated processing at high speed, since longer sized checks may be mailed flat rather than folded. Accordingly, in one preferred application, the envelope may be sent to a recipient in the compact form, for example with a billing statement, and the recipient may unfold the envelope to a second length sized to hold a commercial length check. This dual-length feature presents certain desirable advantages in automated check opening operations. The envelope must usually be slit along three sides to send the check in one direction and the envelope remains in the other, with only sliver cuts needing to be vacuumed away. All untacked or unglued edges are at an angle compatible with automation, i.e. preferably not 90 degrees. Envelopes containing folded checks cannot be put through such an automatic extraction process.

[0031] It is believed that the present invention includes many other embodiments that may not be herein described in detail, but would nonetheless be appreciated by those skilled in the art from the disclosures made. Accordingly, this disclosure should not be read as being limited only to the foregoing examples or only to the designated preferred embodiments. 

I claim:
 1. A variable length mailer comprising: a) a front panel having a first fold line and a second fold line in parallel relation one to the other; said front panel having an extension at one end thereof, this front panel being alternately foldable in a vertical plane in relation to the first or second fold line; b) a rear panel approximately equivalent in length to the length of the front panel and of lesser height than said front panel, said first and second fold lines of the front panel extending along the rear panel; c) a top flap approximately equivalent in length to the front panel, said first and second fold lines of the front panel extending along the top flap; and d) at least one extendable side flap foldable along either the first or second fold line of the front panel to provide a mailer adjusted to varying lengths.
 2. The mailer of claim 1, further comprising printed graphics or text on at least one panel thereof.
 3. A blank for forming a variable length mailer comprising: a) a front panel having a first fold line and a second fold line in parallel alignment to each other, and further having an extension at one end thereof that is of approximately the same height as said front panel; b) a rear panel approximately equivalent in length to the front panel; c) a seal flap approximately equivalent in length to the front panel, said first and second fold lines extending along the top flap; d) a first side flap of fixed length and height, the length thereof being less than the length of said front panel and the height thereof being approximately equivalent to the height of said front panel; and e) a second side flap cooperatively attached to said extension of the front panel. 